Hi,

I am trying to do a thermodynamic problem for practice and my units seem to be stubborn. It gives me the "right units" except it gives me a unit of temperature over a unit of temperature instead of just ft^3/hr. See the snapshot. Any tips for a SMath beginner?





Thanks in advance.

I think it's just a problem with the temperature difference unit

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sergio

Greetings,

Wrote

just a problem with the temperature difference unit
sergio

There is a little bit of a learning curve as it applies to temperature units. Just remember, ℉ is a unit for the acutal thermostat temperature (i.e., 32℉ = 0℃ = 273.15°K) and Δ℉ is the change in temerature (i.e., 32Δ℉ = 17.78Δ℃ = 17.78°K). In other words: unlike other units that share the same value of 'zero' (e.g., 0㎜ = 0㏌ = 0㎞), units for thermostat temperature do not share the same value of zero (i.e., 0℉ ≠ 0℃ ≠ 0°K).

To avoid this issue, you can refer to all your temperature in Kelvin, since Kelvin is based on abosulte zero, the change in Kevin is equal to the temperature in kelvin (e.g., 10°K = 10Δ°K)

With regards to your equation, the culprit is the unit applied to your variable ｢d｣ (PompelmoTell's post illustrates the proper unit), change the unit of '°F to 'Δ°F.

Hope this if of help,
- Kenny Lemens, P.E. ᵂᴵ